Multiple grooving of pavement

ABSTRACT

Particles of pavement removed by cutting thereof into multiple grooves to impart antiskid properties thereto are slurried with water and the slurry disposed of remote from the pavement. Particles of cutting material slurried therewith are reclaimed therefrom for reuse, and pavement particles are optionally recovered from the slurry as well. Such reclamation and recovery may be accomplished by centrifugal methods, such as hydrocycloning.

United States Patent Zuzelo 1 Oct. 24, 1972 [54] MULTIPLE GROOVING 0F 3,572,841 3/1971 Rhodes ..299/39 PAVEMENT 3,598,446 8/ 1971 l-latcher ..299/39 72 Inventor: Edward A. Zuulo 52 Broad Acres 3,608,968 9/1971 Burnett ..299/39 Road, Nat-berth p 19072 2,771,718 11/1956 Gustafson et a1. 1/264 X 2,905,266 9/1959 Pooh ..51/270 X [22] Filed: Feb. 16, 1970 [21] Appl. No.: 11,470 Primary Examiner-Ernest R. Purser Attorney-McClure & Millman [52] US. Cl. ..299/18, 15/320, 51/264,

51/270, 299/39 [57] ABSTRACT [51] Int. Cl ..E01c 23/09 Particles of pavement removed by cutting thereof into Field of Search 8, 39; 175/66, 20 multiple grooves to impart antiskid properties thereto 15/320; 51/264, 270 are slurried with water and the slurry disposed of remote from the pavement. Particles of cutting materi- [56] References C'ted a1 slurried therewith are reclaimed therefrom for P reuse, and pavement P31116165 are 01311011811) recovered from the slurry as well. Such reclamation 3,1 JOhnSPn and recovery may be accompfished centrifugal 2,919,898 l/ 1960 Marwil et al 175/66 methods Such as hydrocycloning 3,407,005 10/1968 Simms et a1. ..299/39 2,680,260 6/1954 Danielsson et al ..l5/320 X 12 Claims, 5 Drawing Figures I L I I CLEAN {2 SLURRYI NG 3' FIRST SECOND -5 USED WATE R AND PICKUP v V SEPARATION r SEPARATION WATE R SECOND 6'6 'v 58 P I C K U P D l A M 0 N D PATENTED 24 I97? 3. 700 849 /6 N E I :2

/{ GEN. DRIVE I CLEAN 3g SLURRYING FIRST SECOND 5 USED WATER AND PICKUP SEPARATION SEPARATION wATER 4 sEOOND v 5 I a PICKUP DIAMOND EDWARD A. ZUZELO M QZA v3-t P Ma k A 770KNE J MULTIPLE GROOVING OF PAVEMENT This invention relates to grooving of pavement to improve traction for vehicles thereon, such as cars on roadways and airplanes on runways, in the interest of improved safety.

It is known to produce, as by abrasive cutting, closely spaced parallel grooves of relatively shallow depth in the pavement of roadways (usually longitudinally) and runways (usually transversely) to improve directional control and stopping ability, especially during wet weather when the wheels of cars and airplanes tend to hydroplane or slide on a thin film of water on the pavement. The grooves not only reduce the amount of water standing on the pavement surface but also provide ready escape paths for such water when encountered by the vehicle wheels. Unfortunately there are potential safety hazards inherent in the grooving operation itself and its aftermath.

A primary object of the present invention is elimination of safety hazards attendant upon or consequent to multiple grooving of pavement.

Another object is improvement in efficiency of multiple grooving of pavement.

A further object is more economical multiple grooving of pavement.

Other objects of this invention, together with means and methods for attaining the various objects will be apparent from the following description and the accompanying diagrams.

FIG. 1 is a partially schematic side elevation of a machine useful according to the present invention in the multiple grooving of pavement;

FIG. 2 is a similar view of auxiliary apparatus shown in trailer form;

FIG. 3 is an enlarged side sectional elevation of a detail of FIG. 1;

FIG. 4 is a sectional plan taken at IVIV of FIG. 3; and

FIG. 5 is a schematic flow diagram applicable to the foregoing in the practice of this invention. H

In general, the objects of the present invention are accomplished, in multiple grooving of pavement to improve traction thereon when wet, wherein particles of pavement material and cutting material result from grooving engagement of cutting means with the pavement at a cutting location, by slurrying such resulting particles with water supplied to the cutting location, collecting such slurry, and reclaiming reusable cutting particles therefrom. Before disposing of at least part of the slurry at a remote location, particles of cutting material slurried therewith are recovered therefrom for reuse, and preferably centrifugally, pavement particles are optionally recovered centrifugally from the slurry as well.

FIG. 1 shows steerable machine having a set of front wheels 13 and a set of rear wheels 15 (only one of each being visible) on pavement l and having frame 11 supported by the wheels and carrying thereon additional components. Shown in block form on the frame at the front are engine 14 and, driven directly by the engine, generator 16 and hydrostatic drive 17. Connected to the generator by suitable electrical leads is motor 18, which drives pump 19, shown in block form on the frame at the rear of the machine. Suspended under the midportion of the frame on retractable support 21 is cutting assembly 20, which is shown fragmentarily in greater detail in FIGS. 3 and 4. Blocked out above the midportion of the frame is a region in which mechanism for retracting and extending or otherwise moving the cutter assembly is located; such mechanism is not shown because it does not form any part of the present invention, and such conventional mechanism as a handwheel worm arrangement may be used to raise and lower the cutter assembly. Alternatively, more sophisticated mechanism for raising or retracting and for lowering or extending the cutter assembly may be employed in conjunction with this invention.

Hydrostatic drive 17, which is shown connected to the front wheels by fluid line 30, preferably is of dualspeed type, such as is well known, capable of providing a suitable over-the-road speed for transport between working sites and a crawl speed for on-site operation. Fluid line 31 connects the hydrostatic drive to the cutter assembly to rotate the cutting discs or blades. Suitable hydraulic motors to which lines 30 and 31 connect to drive the machine and the cutter assembly, respectively, are not shown but are constructed and connected to the wheel axle and the cutter shaft as is well known in the art. Alternatively, the machine may be driven by mechanical coupling to the engine through suitable reduction gearing, and the cutter assembly may be rotated by similar mechanical interconnection; or, if desired, either or both drives may be electric, from one or more engine-driven generators or alternators. It will be apparent, of course, that although front-wheel drive is indicated for the machine itself, that the rear wheels may be driven instead of or in addition to the front wheels. This invention is independent of any particular form of drive of the machine itself or of the cutter assembly, being useful with any suitable forms of drive.

Pump 19 is of dual type, pumping water from a source (located separately) to the cutter assembly through line 32 and pumping resulting slurry from the cutter assembly through return line 34 to a storage location (also located separately) as indicated by arrows. FIG. 2 shows trailer 40 with bed 41 supported on front wheels 43 and rear wheels 45 (only one of each being visible) and carrying reservoir or source tank 42 with inlet 46 for clean water and storage tank 44 with outlet 48 for the slurry or more specifically for used water from the slurry. Normally closed valve 50 may be opened to interconnect the source tank and the storage tank if and when desired. Lines 32 from the clean water source tank and return line 34' to the storage tank are readily attachable to and detachable from respective lines 32 and 34 on the machine of FIG. 1 by means of the fittings shown terminating the lines. Interposed between the return line and the storage tank are two centrifugal separators of conventional hydrocyclone type.

First separator 51 receives slurry from the cutter assembly through line 34', which constitutes the hydrocyclone feed line; the hydrocyclone underflow passes into compartment 53 thereunder, while the overflow passes through line 35 (containing an appropriate pump) to second separator 52, for which it constitutes the hydrocyclone feed line. The underflow from the second separator passes into compartment 54 thereunder, while the overflow passes through line 36 into storage tank 44. First compartment 53 has line 55 (with pump) for fresh water from source tank 42 entering the top and has line 56 (with pump and check valve) for used water leaving the bottom and joining line 35 leading to the second separator. Second compartment 54 has line 58 from the bottom joining line 65 (with dual pump at the junction), which in turn (with check valve) joins line 36 leading to storage tank 44. The respective compartments are openable on the opposite side (not shown) and optionally on the visible side also to facilitate removal of the underflow materials accumulated therein.

Supported underneath the midportion of trailer bed 41 is brush assembly 60, comprising cylindrical rotary brush 62 protruding into contact with the pavement underneath surrounding shroud 63. Line 64 (with pump) leads to jets 68 (one visible) directed from the rear toward the conjunction of the brush with the pavement, while return line 65 from a trough (not visible) formed by the bottom of the shroud joins line 58 (at the last mentioned dual pump) and then joins line 36 leading to the storage tank as aforementioned. Drive chain (or belt) 69 from the rear wheels to the brush rotates it in a direction opposite to the direction of travel of the trailer. It will be understood that the trailer is designed to be detachably secured, as by the indicated mating hitches, to machine to be pulled thereby. The various pumps on the trailer are provided with electrical leads (not shown) to connect with connectors 37 located at the rear of frame 11 of the machine and terminating the illustrated electrical leads from the generator.

FIGS. 3 and 4 show cutter assembly of FIG. 1 on an enlarged scale, in side sectional elevation and sectional plan, respectively. Horizontal shaft 70 is supported at its ends by yoke 21 and carries, spaced equally along the shaft and transversely of the machine itself, a multiplicity of cutting discs or blades 71 detachably secured thereto between spacers 72. Shroud 74 of generally involute cross-sectional form has end plate 76 and surrounds the blades except at the bottom, being closer to the blades at the front and further therefrom at the rear. Except directly under the blades the shroud is closed underneath at the front by relatively small sloping trough 73 connected to return line 33, and at the rear by relatively large sloping trough 75 connected to return line 38. Underneath the rear trough is a multiplicity of jet nozzles 78 fed from manifold 77, which is connected by line 79 to clean water line- 32. The nozzles are spaced under and between adjacent blades and direct the water sideways and forward against the blades and toward the cutting junction of the blades with pavement 1, in which they are forming multiplicity of grooves 100 (one visible). It will be understood that the rotation of the blades against the forward direction of movement of the machine carries the water (and particlesof pavement and of cutter material, which become slurried therewith) forward at the bottom and upward and toward the rear within the shroud to collect mostly in the rear. trough and to a lesser extent in the front trough, from both of which the collected slurry is pumped to the first separator for centrifugal treatment therein.

Operation of the described and illustrated apparatus to practice the present invention is readily understood,

especially with further reference to the simplified flow diagram of FIG. 5, in which the blocks represent process steps or stations and the interconnecting lines are numbered in accordance with the foregoing. Thus, the machine is operated to move forward slowly and to rotate the blades relatively rapidly to cut a multiplicity of shallow parallel grooves closely spaced and extending in the longitudinal direction of machine movement. Clean water is supplied to the. cutting location, where it is slurried with particles of pavement removed by the abrasive cutting and with particles of cutting material (chiefly diamonds) dislodged from the blades themselves. The resulting slurry is picked up and forwarded to the first stage of centrifugal separation, wherein the diamond or other dense particles of cutter material are largely segregated in the underflow, while the overflow slurry of pavement particles passes out the overflow. The underflow is washed with additional clean water in a conventional filtration compartment, optionally with mechanical agitation of the filter elements (usually fine metallic screens), after which the wash water is added to the overflow from the first separation, which then constitutes the feed for the second separation. Of course, the diamonds are recovered manually at suitable intervals for reuse in manufacture of additional cutter blades or for other appropriate use.

In the second centrifugal separation the pavement particles are largely segregated in the underflow, which has a dense ropy consistency and accumulates in the form of a damp sludge, from which some water may be pumped away to the used water storage, which is where the overflow from the second separation also goes. The accumulated sludge is removed manually at appropriate intervals for disposal at a remote site either wet or after drying, whereupon the resulting caked powder is suitable for use as a filler in various cementitious construction materials or the like. Particulate material not picked up at the cutting location is subjected to a second pickup step, as the trailer passes thereover, through the brushing action and supplying of additional slurrying water to the brushing location. The resulting slurry is fed to storage tank 44 via connection with line 65, as already indicated by reference to FIG. 2, but in the event of an appreciable diamond concentration at the brushing location the slurry is optionally fed by alternative connection with line 34, 34 (as in FIG. 5) to the first separation step along with the slurry from the cutting location.

The entire process is continuous and can continue until all the clean water has been used, whereupon most of it will have collected in the storage tank in the form of used water, i.e., containing unseparated pavement particles and perhaps a slight amount of cutter material in particulate form, together with oil, rubber, soil and the like removed from the pavement surface. At such time the trailer may be detached from the machine and be replaced by another trailer having a full tank of clean water and an empty tank for used water, as well as clean compartments for diamonds and forsludge. Alternatively, especially where the pavement being grooved is sufiiciently new not to have been coated heavily with oil, rubber, soil, etc., the clean water and used water tanks may be interconnected by opening the valve therebetween (as suggested by the broken line in FIG. '5), in which event the overall process can be practiced as a closed system, subject to gradual loss of water because of incomplete pickup and gradual increase in unseparated solids concentration. If desired, additional stages of separation may be added to facilitate such recycling, as is especially useful where it is inconvenient, uneconomical, or otherwise impracticable to exchange trailers. In some locations, for example, a source of clean water or an appropriate disposal location for sludge or used water may be too remote to permit single cycling of the water.

Regardless of whether operated in single-cycle or recycle fashion, the present invention avoids flooding the pavement being grooved, and possibly an adjoining traveled lane of pavement to which the water would drain, which is hazardous to traffic. It also avoids leaving an incrustation of pavement particles, such as impairs the effectiveness of the grooving and also presents a hazard when dislodged subsequently, as by jet engines. Economy of operation is effected by recovery of diamonds or other valuable components of the cutter material, as well as by possible use of byproduct particulate pavement material. Other advantages and benefits thereof will accrue and become apparent to those undertaking to practice the invention.

Although a preferred embodiment and certain modifications thereof have been illustrated and described, it will be understood that other modifications may be made therein, as by adding, combining, or subdividing parts or steps, while retaining at least some of the advantages and benefits of this invention. The invention itself is defined in the following claims.

The claimed invention:

1. Procedure for producing multiple parallel grooves in pavement to improve traction thereon when wet, comprising the steps of rotating cutting means in grooving engagement with the pavement at a multiplicity of laterally spaced locations and simultaneously moving the rotating cutting means in the grooving direction, thereby dislodging particles of pavement material and denser particles of reusable cutting material from the cutting means during groove formation; supplying water thereto and thereby forming a slurry of such particles, and collecting such slurry; scrubbing the grooved pavement subsequent to such original slurry formation and subjecting water used in such subsequent scrubbing step to a hydrocycloning step, concentrating particles of reusable cutting material by hydrocycloning the slurry, and so recovering particles of reusable cutting material therefrom; and disposing of the residual slurry containing component particulate pavement material at a remote location.

2. in multiple grooving of pavement to improve traction thereon when wet, including rotating cutting blades comprising diamond particles in contact with the pavement at a cutting location and thereby dislodging particles of pavement material from the pavement and reusable diamond particles from the cutting blades, the improvement comprising reclaiming dislodged diamond particles for subsequent reuse, including subsequently scrubbing the pavement at the former cutting location, thereby forming a slurry of dislodged particles in water, and collecting such slurry for reclamation of diamond particles therefrom.

3. Process according to claim 2, including performing the scrubbing step while the pavement is wet from slurrying performed previously in the vicinity of the cutting location.

4. In multiple grooving of pavement utilizing cutting material comprising diamonds, wherein particles of pavement material are dislodged from the pavement and reusable diamonds are dislodged from the cutting material and the various particles are slurried together with water, the improvement comprising recovering some of the slurried particulate material in the immediate vicinity of the cutting operation, thereafter scrubbing the grooved pavement, and recovering residual particulate material left thereon by the cutting operation.

5. Process according to claim 4, including the subsequent steps of separating from the recovered mate rial predominantly liquid and predominantly solid fractions.

6. Process according to claim 5, including the further step of separating from the predominantly solid material a first fraction consisting essentially of pavement material and a second fraction consisting essentially of cutting material.

7. Process according to claim 6, including the step of reclaiming diamonds from the fraction consisting essentially of cutting material.

8. Process according to claim 4, wherein water is supplied to the scrubbing location.

9. Process according to claim 8, including the step of brushing the grooved pavement at the scrubbing location.

10. Procedure for producing multiple parallel grooves in pavement to improve traction thereon when wet, comprising the steps of rotating cutting means in grooving engagement with the pavement at a multiplicity of laterally spaced locations and simultaneously moving the rotating cutting means in the grooving direction, thereby dislodging particles of pavement material and denser particles of reusable cutting material from the cutting means during groove formation; supplying water thereto and thereby forming a slurry of such particles, and collecting such slurry; scrubbing the grooved pavement subsequent to such original slurry formation and subjecting water used in such subsequent scrubbing step to a separation step, concentrating particles of reusable cutting material, and so recovering particles of reusable cutting material therefrom; and disposing of the residual slurry containing component particulate pavement material at a remote location.

11. In multiple grooving of pavement to improve traction thereon when wet, including rotating cutting blades comprising reusable abrasive particles in contact with the pavement at a cutting location and thereby dislodging particles of pavement material from the pavement and reusable abrasive particles from the cutting blades, the improvement comprising reclaiming dislodged abrasive particles for subsequent reuse, including subsequently scrubbing the pavement at the former cutting location, thereby forming a slurry of dislodged particles therefrom.

12. In multiple grooving of pavement utilizing cutting material comprising diamonds or similar abrasive particles, wherein particles of pavement material are dislodged from the pavement and reusable abrasive particles are dislodged from the cutting material and the various particles are slurried together with water, the improvement comprising recovering some of the slurried particulate material in the immediate vicinity of the cutting operation, thereafter scrubbing the grooved pavement, and recovering residual particulate material left thereon by the cutting operation. 

1. Procedure for producing multiple parallel grooves in pavement to improve traction thereon when wet, comprising the steps of rotating cutting means in grooving engagement with the pavement at a multiplicity of laterally spaced locations and simultaneously moving the rotating cutting means in the grooving direction, thereby dislodging particles of pavement material and denser particles of reusable cutting material from the cutting means during groove formation; supplying water thereto and thereby forming a slurry of such particles, and collecting such slurry; scrubbing the grooved pavement subsequent to such original slurry formation and subjecting water used in such subsequent scrubbing step to a hydrocycloning step, concentrating particles of reusable cutting material by hydrocycloning the slurry, and so recovering particles of reusable cutting material therefrom; and disposing of the residual slurry containing component particulate pavement material at a remote location.
 2. In multiple grooving of pavement to improve traction thereon when wet, including rotating cutting blades comprising diamond particles in contact with the pavement at a cutting location and thereby dislodging particles of pavement material from the pavement and reusable diamond particles from the cutting blades, the improvement comprising reclaiming dislodged diamond particles for subsequent reuse, including subsequently scrubbing the pavement at the former cutting location, thereby forming a slurry of dislodged particles in water, and collecting such slurry for reclamation of diamond particles therefrom.
 3. Process according to claim 2, including performing the scrubbing step while the pavement is wet from slurrying performed previously in the vicinity of the cutting location.
 4. In multiple grooving of pavement utilizing cutting material comprising diamonds, wherein particles of pavement material are dislodged from the pavement and reusable diamonds are dislodged from the cutting material and the various particles are slurried together with water, the improvement comprising recovering some of the slurried particulate material in the immediate vicinity of the cutting operation, thereafter scrubbing the grooved pavement, and recovering residual particulate material left thereon by the cutting operation.
 5. Process according to claim 4, including the subsequent steps of separating from the recovered material predominantly liquid and predominantly solid fractions.
 6. Process according to claim 5, including the further step of separating from the predominantly solid material a first fraction consisting essentially of pavement material and a second fraction consisting essentially of cutting material.
 7. Process according to claim 6, including the step of reclaiming diamonds from the fraction consisting essentially of cutting material.
 8. Process according to claim 4, wherein water is supplied to the scrubbing location.
 9. Process according to claim 8, including the step of brushing the grooved pavement at the scrubbing location.
 10. Procedure for producing multiple parallel grooves in pavement to improve traction thereon when wet, comprising the steps of rotating cutting means in grooving engagement with the pavement at a multiplicity of laterally spaced locations and simultaneously moving the rotating cutting means in the grooving direction, thereby dislodging particles of pavement material and denser particles of reusable cutting material from the cutting means during groove formation; supplying water thereto and thereby forming a slurry of such particles, and collecting such slurry; scrubbing the grooved pavement subsequent to such original slurry formation and subjecting water used in such subsequent scrubbing step to a separation step, concentrating particles of reuSable cutting material, and so recovering particles of reusable cutting material therefrom; and disposing of the residual slurry containing component particulate pavement material at a remote location.
 11. In multiple grooving of pavement to improve traction thereon when wet, including rotating cutting blades comprising reusable abrasive particles in contact with the pavement at a cutting location and thereby dislodging particles of pavement material from the pavement and reusable abrasive particles from the cutting blades, the improvement comprising reclaiming dislodged abrasive particles for subsequent reuse, including subsequently scrubbing the pavement at the former cutting location, thereby forming a slurry of dislodged particles therefrom.
 12. In multiple grooving of pavement utilizing cutting material comprising diamonds or similar abrasive particles, wherein particles of pavement material are dislodged from the pavement and reusable abrasive particles are dislodged from the cutting material and the various particles are slurried together with water, the improvement comprising recovering some of the slurried particulate material in the immediate vicinity of the cutting operation, thereafter scrubbing the grooved pavement, and recovering residual particulate material left thereon by the cutting operation. 